The woman was found on the ground in Anstruther St by a passer-by shortly before 3pm after walking across the bridge from the Campaspe River bike track area.
Echuca police Detective Sergeant Shane Kervin said she had clear facial injuries, along with multiple scratches and lacerations to her body and torso.
“She’s obviously traumatised and not yet in a position to tell police exactly what happened,” he said.
“What we’ve been able to obtain is that she appears to have been assaulted.
“Once she is well enough, we will investigate further.
“The parties are not known to each other. It looks like it was a chance encounter, wrong place, wrong time.
“But there appears to have been multiple people involved.”
Police are appealing for anyone who was near the Campaspe River bike track about 3pm on Thursday, October 8, and saw anything suspicious to come forward.
“The woman was distressed, but she wasn’t unconscious when she was found,” Sgt Kervin said.
Advanced Life Support paramedics attended after Ambulance Victoria was called about 2.55pm.
The woman was taken by road ambulance to hospital in a stable condition with serious but non-life-threatening injuries.
Police are continuing to investigate the circumstances surrounding the assault.
Anyone with information or who witnessed anything around the Campaspe River bike track about 2.45pm is urged to contact Echuca police on 5483 1500 or Crime Stoppers on 1800 333 000.